Ultrasonographic Appearance of a Posterior Lenticonus in a Cat.

Abstract

The objective of this study is to present high-quality and up-to-date ocular ultrasonographic images and videos of a posterior lenticonus with concomitant mature cataract in a cat. Additionally, the clinical findings, surgical treatment, and outcome are reported for completeness and to confirm the diagnosis. An 8-year-old castrated male domestic shorthair cat presented due to unilateral cataract. Ophthalmological examination revealed a mature cataract without clinically detectable uveitis. Hematological and biochemical analyses were unremarkable, and tests for common infectious diseases associated with feline uveitis were negative. Electroretinography and ocular ultrasound were performed as part of the presurgical planning for phacoemulsification. Retinal function was normal. Ultrasonographic examination revealed a severely distorted shape of the posterior lens capsule (PLC) with hyperechoic material protruding into the vitreous body. Neither a PLC fibrovascular plaque nor a persistent hyaloid artery was identified. These findings were interpreted as a possible rupture of the posterior lens capsule with lens material extruding into the vitreous body. Posterior lenticonus was considered a less likely differential diagnosis. The owner elected to proceed with phacoemulsification surgery. Intraoperatively, the posterior lens capsule was found to be intact. An axial posterior lenticonus with cataractous lens material bulging together with the capsule into vitreous was identified. An intraocular lens was successfully implanted. Given the better surgical prognosis compared to capsule ruptures, posterior lenticonus, although rare, should be considered a differential diagnosis, particularly when a cone-shaped protrusion lacking Doppler signal is identified at the posterior lens capsule extending into the vitreous body.